SpCrossreactivity
The specificity of free PSA kit was determined by measuring interference from high concentrations of human serum proteins, hormones, and tumor markers. No cross reactivity was observed. The human PSA ELISA kit #1500 detects total PSA. ADI has another ELISA kit #1510 for free PSA. Human free PSA ELISA kit species crossreactivity with PSA from other species (mouse, rat, and monkey) has not been established.

Human Prostate-Specific Antigen (PSA) is a protein expressed only in the prostatic secretory epithelium. It is a protease with chymotrypsin-like activity. Its function is to liquefy semen through hydrolysis of semenogelin. PSA occurs in serum in at lea